Uitwerking
\(
\eqalign{
& 2 \cdot \cos (x) = 0 \cr
& \cos (x) = 0 \cr
& x = \frac{1}
{2}\pi + k \cdot \pi \cr}
\)
...en dat is het dan...
It's finally #Summer Let's go exploring! pic.twitter.com/DDRW8yNM0M
— Calvin and Hobbes (@Calvinn_Hobbes) 21 juni 2017